An arrangement provides a power supply for low voltage circuits that is connected to receive and store energy from a power electronics switch that is connected to an alternating current supply. The power supply is operative over a wide range of input and regardless of the operating status of the power electronics switch. For each half cycle of the alternating current which the power electronic switch is to be rendered conductive, the arrangement delays for a predetermined time duration the control of the power electronic switch at the zero crossing of the half cycle. During the predetermined time duration, the power supply charges an energy storage device with sufficient energy to supply the low voltage circuit until the next half cycle.
Legal claims defining the scope of protection, as filed with the USPTO.
1. An arrangement for supplying power to a low voltage load from a power electronic switch supplied by an alternating current supply, the arrangement comprising: first means for delaying the control of the power electronic switch for a predetermined time duration at the zero crossing of each half wave of the alternating current supply for which the power electronic switch is to be rendered conductive; second means connected to the power electronic switch for storing energy during said predetermined time duration; and third means for supplying the load via energy from the energy storage device during the remainder of the half cycle.
2. The arrangement of claim 1 wherein said second means comprises energy storage means and means for charging said energy storage means.
3. The arrangement of claim 2 wherein said second means further comprises means for blocking a discharge of energy from said energy storage means to the power electronic switch.
4. The arrangement of claim 2 wherein said charging means comprises a full wave rectifier.
5. The arrangement of claim 1 wherein said third means comprises constant current means for supplying current to the load.
6. The arrangement of claim 5 wherein said third means further comprises filter means arranged to receive current from said constant current means.
7. The arrangement of claim 5 wherein said constant current means comprises a series connected array of electronic devices.
8. The arrangement of claim 7 wherein said constant current means further comprises means connected to each of said electronic devices for setting a predetermined constant current of said constant current means.
9. The arrangement of claim 7 wherein said electronic devices comprise n-channel depletion-mode MOSFETS.
10. The arrangement of claim 9 wherein said constant current means further comprises a resistor connected between the gate and source of each of the MOSFETS.
11. The arrangement of claim 9 wherein said constant current means further comprises a speed-up circuit connected across said resistor.
12. The arrangement of claim 7 wherein said constant current means further comprises a diode being connected across each of said electronic devices.
13. The arrangement of claim 1 wherein said second means comprises a full wave rectifier connected across the power electronic switch and a capacitor connected to said full wave rectifier.
14. An arrangement connected across a source of power in an alternating current circuit comprising first means responsive to a range of input from a brief pulse every half-cycle to a full half cycle for supplying continuous power to a load, said first means comprising energy storage means and constant current means responsive to said energy storage means.
15. The arrangement of claim 14 wherein said brief pulse has a peak voltage which is at least an order of magnitude less than the peak voltage of the alternating current.
16. The arrangement of claim 15 wherein said brief pulse has a duration that is less than 10% of a half cycle of the alternating current.
17. A power supply connected across a power electronic switch supplied with an alternating current supply and being selectively rendered conductive each half cycle, the power supply comprising: energy storage means for storing energy during a small portion of each half cycle of the waveform; regulator means; and constant current source means responsive to said energy storage means and supplying current to said regulator means.
18. A method of supplying power to a low voltage load from an alternating current supply across a power electronic switch comprising the steps of: delaying the control of the power electronic switch for a predetermined time duration at the zero crossing of each half wave of the alternating current supply for which the power electronic switch is to be rendered conductive, charging an energy storage device during the predetermined time duration; and supplying the load via energy from the energy storage device during at least the remainder of the half cycle.
19. The method of claim 18 wherein said charging step comprises storing sufficient energy in the energy storage device to supply the load for a time period greater than a half cycle of the alternating current.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
April 24, 2000
August 7, 2001
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